In this type of compressor, with conventional units having compressor bundles whose weight is in up to about 20-ton class, the compressor bundle is inserted into a chamber by sliding it thereinto from an opening provided at one end of the chamber. However, with a recent increase in the size of compression equipment, there are now 100-ton class compressor bundles, and it is very difficult to accommodate such a heavy compressor bundle in a chamber by sliding it thereinto. Because of this, as disclosed in the Publication of Japanese Patent No. 3049059, rollers are provided in the bundle casing (chamber), and the compressor bundle is placed on the rollers so that it can be inserted smoothly.
A clearance between an outer circumferential portion of the compressor bundle and an inner circumferential wall surface of the chamber is set to be very small in order to prevent leakage of compression fluid, and even for a large compressor bundle whose outer diameter exceeds 2 m, the clearance described above is not even 1 mm. Because of this, if the compressor bundle tilts toward the chamber even slightly during insertion into the chamber, the outer circumferential portion of the compressor bundle interferes with the inner circumferential wall surface of the chamber, which causes damage, dents, etc., which would deteriorate the airtightness, thus, deteriorating the quality of the compressor. Accordingly, in a technique disclosed in the Publication of Japanese Patent No. 3049059, the rollers provided in the chamber are made height adjustable by means of screw jacks, and, when the compressor bundle tilts, the heights of rollers are adjusted with the screw jack to correct the tilting.